Das Puzzle Spiel is a LaTeX package (dps) for creating a puzzle, a
message actually, and a series of questions and answers. The
document consumer matches the questions with the answers. With
each match, another letter appears in the puzzle. Upon completion
of all questions, the message hidden in the puzzle is revealed.
The puzzle is primarily designed for the screen, but you can
optionally create the game for paper.

The package itself is distributed as a zip file embedded in the
package documentation.